#include<stdio.h>

int main(void)
{
	int r,g,b,sum=0,min;
	scanf("%d%d%d",&r,&g,&b);
	sum+=r/3;
	sum+=g/3;
	sum+=b/3;
	r%=3;
	g%=3;
	b%=3;
	min=r;
	if(g<min)
	{
		min=g;
	}
	if(b<min)
	{
		min=b;
	}
	
	printf("%d",sum+min);
	
	return 0;
}
